This view of the twilight sky and Martian horizon taken by NASA's Curiosity Mars rover includes Earth as the brightest point of light in the night sky. Earth is a little left of center in the image, and our moon is just below Earth.

This frame from an animation from NASA's Mars rover Curiosity shows the rover drilling into rock target 'Cumberland.' The drilling was performed during the 279th Martian day, or sol, of the Curiosity's work on Mars (May 19, 2013).

This image from the Mars Hand Lens Imager on NASA's Mars rover Curiosity shows the patch of rock cleaned by the first use of the rover's Dust Removal Tool (DRT). The tool is a motorized, wire-bristle brush on the turret at the end of the rover's arm.

The two bodies in this portion of an evening-sky view by NASA's Mars rover Curiosity are Earth and Earth's moon. The rover's Mast Camera (Mastcam) imaged them in the twilight sky of Curiosity's 529th Martian day, or sol (Jan. 31, 2014).

This pair of images from the Mast Camera on NASA's Curiosity rover shows the upper portion of a wind-blown deposit dubbed 'Rocknest.' At left, colors are unmodified, showing the scene as it would appear on Mars, which has a dusty red-colored atmosphere.

This charged couple device (CCD) is part of the CheMin instrument on NASA's Curiosity rover. When CheMin directs X-rays at a sample of soil, this imager, which is the size of a postage stamp, detects both the position and energy of each X-ray photon.

A conventional X-ray diffraction instrument (left) is the size of a large refrigerator, in contrast to the compact size of the Chemistry and Mineralogy (CheMin) instrument on NASA's Curiosity rover (top right).

This focus-merge image from the Mars Hand Lens Imager (MAHLI) on the arm of NASA's Mars rover Curiosity shows a rock called 'Burwash.' The rock has a coating of dust on it. The coarser, visible grains are windblown sand.

Sample material from the fourth scoop of Martian soil collected by NASA's Mars rover Curiosity is on the rover's observation tray in this image taken during the mission's 78th Martian sol, (Oct. 24, 2012) by Curiosity's left Navigation Camera.

The Chemistry and Camera (ChemCam) instrument on NASA's Mars rover Curiosity used its laser and spectrometers to examine what chemical elements are in a drift of Martian sand during the mission's 74th Martian day, or sol (Oct. 20, 2012).

The mission's science team assessed the bright particles in this scooped pit to be native Martian material rather than spacecraft debris as seen in this image from NASA's Mars rover Curiosity as it collected its second scoop of Martian soil.

This image from NASA's Mars rover Curiosity shows a small bright object on the ground beside the rover at the 'Rocknest' site. The rover team has assessed this object as debris from the spacecraft, possibly from the events of landing on Mars.

This image from NASA's Curiosity rover just after discarding a soil sample as part of its first 'decontamination' exercise. A small amount of remnant material is visible inside the delivery tube, which is magnified in the blow-up at lower right.

In this image, the scoop on NASA's Curiosity rover shows the larger soil particles that were too big to filter through a sample-processing sieve that is porous only to particles less than 0.006 inches (150 microns) across.

This image shows the wall of a scuffmark NASA's Curiosity made in a windblown ripple of Martian sand with its wheel. The upper half of the image shows a small portion of the side wall of the scuff and a little bit of the floor of the scuff.

This pairing illustrates the first time that NASA's Mars rover Curiosity collected a scoop of soil on Mars. At right, the ground location 'Rocknest,' at left, after the scoop of sand and dust had been removed.

This image from NASA's Curiosity shows a scoop full of sand and dust lifted by the rover's first use of the scoop on its robotic arm. In the foreground, near bottom of this image, the bright object visible on the ground might be a piece of rover hardware.